Crypto: Polymarket and Kalshi see Democrats taking back the US Congress

A few months before the US mid-term elections, crypto prediction markets have already chosen their side. On Polymarket and Kalshi, more than $12.5 million has been committed to a scenario that worries Republicans: a takeover of Congress by the Democrats. This rise in betting comes as Donald Trump continues unfavorable polls, gradually transforming these crypto platforms into real political barometers followed even in Washington circles.

Polymarket and Kalshi see Democrats taking back Congress

Traders active on Polymarket and Kalshi converge on the same scenario for the 2026 midterm elections: a Democratic victory in the US Congress. On Polymarket, the market displays over $7 million in volume traded, while Kalshi exceeds $5.5 million.

The implied probabilities currently displayed by the two platforms show a clear investor preference for a Democratic shift:

• Polymarket attributes 47% chance of Democratic control of the House and Senate;
• The scenario “Republican Senate + Democratic Chamber” reached 34%;
• A total Republican victory is limited to 19%;
• On Kalshi, the probability of a total victory of the Democrats spring at 45%
  ;
• The scenario of an entirely Republican Congress reaches 25%.

This convergence is attracting attention because these platforms rely on financial markets powered by real money. Participants are not responding to an opinion poll: they are taking monetary positions on future political events.

The resolution mechanisms used by Polymarket and Kalshi are based on the official results of the American Congress or on projections validated by the major American media. As volumes increase, these platforms reinforce their status as alternative barometers of American political life.

Donald Trump's weakness fuels traders' bets

The dynamics observed in predictive markets can also be explained by the deterioration of on-chain political data surrounding Donald Trump and the Republican Party. Several surveys cited in the article show a marked decline in the popularity of the American president. Quinnipiac attributes to Trump only 34% approval compared to 58% disapproval. The AP-NORC poll shows 37% favorable opinions compared to 62% unfavorable opinions. The New York Times/Siena tracker evoked also an approval rating of 37%, billed as the lowest level of his second term.

Thus, the political climate is also becoming complicated for Republicans in Congress. A Gallup poll relieving a Congressional approval rating limited to 10%, compared to 86% disapproval. At the same time, the Democrats would retain a national lead of between D+5 and D+7on the “generic nerd”a closely watched indicator before the American elections. Historically, the president's party has regularly lost seats in midterm elections since World War II, citing the precedents of George W. Bush in 2006 and Barack Obama in 2010.

A Democratic victory in the midterms could profoundly change the American political balance. Several possible consequences are mentioned: blocking of Donald Trump's legislative agenda, end of easier recourse to the reconciliation procedure, multiplication of parliamentary investigations and new tensions around the American debt ceiling. Through Kalshi and Polymarket, the crypto market above all shows that they are no longer limited to cryptos. They are gradually becoming spaces where investors, traders and political observers try to anticipate the future balance of power of the world's leading power.